How exaclty Emry cost reduction works?
Asked by pedroedmarcos 1 year ago
Hey there,
I just saw a gameplay on a video that the guy played a Emry, Lurker of the Loch and I got really confused. Here is the board state:
The player has a Sensei's Divining Top, a Gilded Goose and a food token on the board and a Emry on his hand. Then he casts the Emry for only a blue tapping the goose and sacrificing the food for a blue mana. But since he sacrificed the food token he does not have 2 artifcats anymore right? So, why Emry costs only a blue? I thought it was a missplay but on the comments it was said it was correct. I really don get it.
I will not post the video, cause I'm not sure if its allowed here.
pedroedmarcos says... #2
Wait, so There is an "Announce spell step" and a "Paying the cost of the spell step" on the casting of the spell ? Can you show me the exact rule? Cause I'm sure that I will have to explain prove this to other players as well.
June 27, 2022 3:50 p.m.
Rhadamanthus says... #3
Sure, no problem. Here are the relevant rules from Section 601 of the Comprehensive Rules, "Casting Spells":
601.2. To cast a spell is to take it from where it is (usually the hand), put it on the stack, and pay its costs, so that it will eventually resolve and have its effect. Casting a spell includes proposal of the spell (rules 601.2a–d) and determination and payment of costs (rules 601.2f–h). To cast a spell, a player follows the steps listed below, in order. A player must be legally allowed to cast the spell to begin this process (see rule 601.3). If a player is unable to comply with the requirements of a step listed below while performing that step, the casting of the spell is illegal ; the game returns to the moment before the casting of that spell was proposed (see rule 727, “Handling Illegal Actions”).
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601.2f The player determines the total cost of the spell. Usually this is just the mana cost. Some spells have additional or alternative costs. Some effects may increase or reduce the cost to pay, or may provide other alternative costs. Costs may include paying mana, tapping permanents, sacrificing permanents, discarding cards, and so on. The total cost is the mana cost or alternative cost (as determined in rule 601.2b), plus all additional costs and cost increases, and minus all cost reductions. If multiple cost reductions apply, the player may apply them in any order. If the mana component of the total cost is reduced to nothing by cost reduction effects, it is considered to be {0}. It can’t be reduced to less than {0}. Once the total cost is determined, any effects that directly affect the total cost are applied. Then the resulting total cost becomes “locked in.” If effects would change the total cost after this time, they have no effect.
601.2g If the total cost includes a mana payment, the player then has a chance to activate mana abilities (see rule 605, “Mana Abilities”). Mana abilities must be activated before costs are paid.
601.2h The player pays the total cost. First, they pay all costs that don’t involve random elements or moving objects from the library to a public zone, in any order. Then they pay all remaining costs in any order. Partial payments are not allowed. Unpayable costs can’t be paid.
Rhadamanthus says... Accepted answer #1
It's because calculating the total cost to cast a spell and paying those costs happen in different steps of the process. In your example, when the players get to the cost-calculating step there are still 2 artifacts, so Emry's total cost is calculated as . Then after that it's time to activate mana abilities and start paying costs. The game won't back up to re-calculate the cost of the spell, even if something related to the cost calculation changes. In your example that means Emry's cost remains locked in at even when the player uses the Goose's ability to sacrifice a Food for mana.
June 27, 2022 1:58 p.m.